Cylindrical elongated furnace for treating material at high temperature and under high pressure

ABSTRACT

A vertical furnace for treating material at high temperature and under high pressure has a stand into which a cylindrical pressure chamber is introduced. This stand is formed of a high pressure cylinder with top and bottom end closures which project into the cylinder. A furnace chamber is formed within the pressure cylinder by two hat-shaped parts with insulating material between them. These parts rest on an annular portion of the bottom closure. The inner part of the bottom closure is removable for charging the furnace.



1. Vertical furnace, preferably for hot isostatic compaction of powder bodies, comprising a stand, a cylindrical pressure chamber suspended in the stand and comprising a high pressure cylinder and top and bottom end closures projecting into the pressure chamber, means forming a furnace chamber within the pressure cylinder and insulation arranged between the furnace chamber and the walls of the pressure chamber comprising an insulating part in the shape of a sealed lid which is formed of at least two separate parts each comprising a transverse portion and a cylindrical wall extending downwardly from the periphery of said transverse portion, said parts being closed in a gas-tight manner at the top and with insulation filling the space between the transverse portions.
 2. Furnace according to claim 1, in which the bottom end closure includes an annular part projecting into the pressure chamber forming part of a divided lower end closure, the opening of said annular part constituting the charging opening, said separate parts being supported by said annular part.
 3. Furnace according to claim 2, in which one separate part comprises two tubular parts with insulation therebetween and a gas-tight lid connected to these two tubular parts, and the other separate part is closed at the top and arranged inside the lid.
 4. Furnace according to claim 2, having inside the inner separate insulating part a heating element which rests on the annular part of the end closure.
 5. Furnace according to claim 4 having bushings for supply of energy to the heating element arranged in the annular part of the lower end closure.
 6. Furnace according to claim 1, in which the cylindrical part of the insulating part comprises at least three tubular parts arranged one inside the other with insulating material therebetween.
 7. Furnace according to claim 6, in which the material of the inner tubular part has lower coefficient of thermal expansion than the material of the surrounding tubes.
 8. Furnace according to claim 6, in which a lid is joined to the two outer tubular parts constituting therewith one of said separate parts.
 9. Furnace accOrding to claim 6, having pressure-equalizing openings connecting between the tubular parts with other spaces inside the pressure chamber. 